Adding custom images to list items

There are many items in lists that are not just books. There is currently no way of adding an image to a list item. These items all look very unintuitive and bland without an image attached to them and it remains difficult to foster engagement in an increasingly slick and demanding space (the internet) with the service when a list looks so.... Empty? Like it's circa 1992? It's fine if there's JUST books but if there's an ebook or any other resource there's just a blank square and it makes the lists more difficult to read and a little confusing. Thanks very much!